256 
MERRILL. 
perhaps the most remarkable find in the Philippines in the history of 
recent botanical exploration of the Archipelago, as this small family is 
almost entirely Australian, six genera being generally recognized, of 
which four, Juncella, Brizula , Aphelia and Alepyrum , are confined to 
Australia, New Zealand and Tasmania, and a fifth, Gaimardia of two 
species, confined to New Zealand, Cape Horn and the Falkland Islands. 
The sixth genus, Centrol&pis , is represented by about twenty species, of 
which one is found in southern Asia (Cambodia), one on Mount Halcon 
and the remainder in south Australia and Tasmania. Dianella caerulea, 
the genus being a characteristic Australian one, extends from Australia 
through New Guinea to Luzon. Pater sonia lowii Stepf, known from 
Borneo and Mindoro, is essentially an Australian type, two species of 
the genus being found on Mount Kinabalu, North Borneo, one extending 
to Mount Halcon, Mindoro, the remaining species, about nineteen, being 
confined to Australia. HalorrJiagis halconensis Merr., the fourth spe.cies 
of the genus to be found in the Philippines, is also an Australian type, 
the genus being largely developed in Australia and for the greater part 
confined to that continent. Didiscus saniculcefolius Merr., of Mindoro 
and Borneo, is also an Australian type, twelve species of the genus being 
Australian, one New Caledonian, and one Mindoro and Bornean. Cla- 
dium latifolium Merr., is one of the comparatively few species of the 
genus found outside of Australia. The Australian element in the 
Philippines has previously been known to be rather large and charac- 
teristic, and it is considerably augmented by the species enumerated 
above. 
I have advanced elsewhere 5 the belief that Mindoro is probably the one 
part of the group which has remained continuously above water for a 
longer period of time that any of the surrounding islands, and a part of 
it at least may have been so from the time that it was connected with the 
great land-mass of the ancient Malayan continent. The geological struc- 
ture of the island, especially that part of it in the Halcon area, seems to 
be quite similar to that of Mount Kinabalu, North Borneo, so far as I 
can determine from available descriptions of the latter, and entirely dif- 
ferent from that of the islands in closest proximity to it, namely Luzon 
and others. The presence only in Mindoro of the one large mammal 
in the Philippines ( Bubalus mindorensis) *is evidence in favor of the 
above hypothesis. Much is known of the avifauna of the island and in 
this character Mindoro is apparently related Avith Borneo through Pala- 
wan, rather than with its nearer neighbor, Luzon. The presence of 
a decided Bornean and Australian element in the flora at the higher 
altitudes on Halcon also indicates previous and close relationships with 
the great land-masses to the East and South, but I find that this botanical 
5 This Journal, Sec. A. Gen. Sci. ( 1907) , 2, 201. 
